Method and system for an adaptive automatic gain control (AGC) reference for HSDPA and WCDMA

Abstract

In a method and system for an adaptive automatic gain control (AGC) reference for HSDPA and WCDMA, A RF receiver, comprising a RF front-end, may receive a signal comprising a pilot signal via WCDMA or HSDPA. The operation mode of the RF front-end of the RF receiver may be determined based on the received signal components such as a HS-PDCH, a HS-SCCH, and/or a CPICH. The received signal strength information (RSSI) of the received signal may be determined from the output of a matched filter within the RF receiver. A true RSSI, which may be indicated by the received signal code power (RSCP), may be determined based on the pilot symbols over the CPICH. The operation mode determined for the receiver's RF front-end, the determined RSSI, and the determined CPICH_RSCP, may be provided as inputs to an automatic-gain-control (AGC) loop or circuit within the receiver front-end.

1. A method for processing signals, the method comprising:
 receiving a wireless signal and a corresponding pilot signal by a wireless receiver; 
 determining signal strength information of said wireless signal; 
 determining an air-interface specific operating mode of said wireless receiver associated with said reception of said received wireless signal; and 
 adaptively adjusting a gain of an automatic gain control (AGC) circuit within said wireless receiver based on said signal strength information and air-interface specific operating mode. 
 
     
     
       2. The method according to  claim 1 , wherein said receiving comprises receiving a wireless signal transmitted via a Wideband CDMA (W-CDMA) operating mode or High-Speed Downlink Packet Access (HSDPA) operating mode. 
     
     
       3. The method according to  claim 1 , wherein said determining said air-interface specific operating mode comprises determining said air-interface operating mode as being a WCDMA operating mode or an HSDPA operating mode. 
     
     
       4. The method according to  claim 1 , wherein said determining said signal strength information comprises determining received signal strength information (RSSI) and received signal code power (RSCP) strength of said wireless signal. 
     
     
       5. The method according to  claim 1 , wherein said determining said received signal strength information comprises processing an output from a match filter within said wireless receiver, wherein said match filter is operable to process a digital RF signal from an output of an analog-to-digital conversion (ADC). 
     
     
       6. The method according to  claim 4 , wherein said determining said received signal code power (RSCP) strength of said wireless signal comprises determining said received signal code power (RSCP) strength from said corresponding pilot signal. 
     
     
       7. The method according to  claim 4 , wherein determining said signal strength information of said wireless signal comprises comparing said received signal strength information of said wireless signal and said received signal code power strength from said corresponding pilot signal of said wireless signal with selected threshold values. 
     
     
       8. The method according to  claim 7 , wherein said adaptively adjusting comprises adaptively adjusting an analog-to-digital conversion (ADC) within said wireless receiver based on said comparison. 
     
     
       9. The method according to  claim 7 , wherein said comparing comprises selecting said threshold values based on said air-interface specific operating mode of said wireless receiver. 
     
     
       10. The method according to  claim 1 , wherein said adaptively adjusting comprises adaptively adjusting an analog-to-digital conversion (ADC) within said wireless receiver based on a speed of said wireless receiver, when said wireless receiver is in a HSDPA operating mode. 
     
     
       11. A system for processing signals, the system comprising:
 one or more circuits in a wireless receiver, wherein said one or more circuits are operable to receive a wireless signal and a corresponding pilot signal by a wireless receiver; 
 said one or more circuits are operable to determine signal strength information of said wireless signal and to determine an air-interface specific operating mode of said wireless receiver associated with said reception of said received wireless signal; and 
 said one or more circuits are operable to adaptively adjust a gain of an automatic gain control (AGC) circuit within said wireless receiver based on said signal strength information and air-interface specific operating mode. 
 
     
     
       12. The system according to  claim 11 , wherein said signal is transmitted via a Wideband CDMA (W-CDMA) operating mode or High-Speed Downlink Packet Access (HSDPA) operating mode. 
     
     
       13. The system according to  claim 11 , wherein said air-interface specific operating mode of said wireless receiver is a WCDMA operating mode or an HSDPA operating mode. 
     
     
       14. The system according to  claim 11 , wherein said signal strength information of said wireless signal comprises received signal strength information (RSSI) and received signal code power (RSCP) strength. 
     
     
       15. The system according to  claim 11 , wherein said one or more circuits are operable to determine said received signal strength information of said wireless signal from an output of a match filter within said wireless receiver, wherein said match filter is operable to process a digital RF signal from an output of an analog-to-digital conversion (ADC). 
     
     
       16. The system according to  claim 14 , wherein said one or more circuits are operable to determine said received signal code power (RSCP) strength from said corresponding pilot signal. 
     
     
       17. The system according to  claim 14 , wherein said one or more circuits are operable to compare said received signal strength information of said wireless signal and said received signal code power strength from said corresponding pilot signal with selected threshold values. 
     
     
       18. The system according to  claim 17 , wherein said one or more circuits are operable to adaptively adjust an analog-to-digital conversion (ADC) within said wireless receiver based on said comparison. 
     
     
       19. The system according to  claim 17 , wherein said one or more circuits are operable to select said threshold values based on said air-interface specific operating mode of said wireless receiver. 
     
     
       20. The system according to  claim 11 , wherein said one or more circuits are operable to adaptively adjust an analog-to-digital conversion (ADC) within said wireless receiver based on a speed of said wireless receiver, when said wireless receiver is in a HSDPA operating mode.